The correct operation of an integrated circuit may depend upon a power supply of the integrated circuit complying with an operating specification, for example, the voltage of the power supply remaining within an allowed voltage range. If the power supply of the integrated circuit fails to comply with the operating specification, the integrated circuit may operate incorrectly, for example, the values stored in memory cells of the integrated circuit may be corrupted. Corruption of memory cells may cause continued improper operation of the integrated circuit. For example, an integrated circuit may provide various operating mode registers that are initialized at the startup of an application using the integrated circuit, and corruption of an operating mode register may enable an operating mode that is unsuitable for the application.
An integrated circuit may provide a power failure detection circuit that detects whether the power supply of the integrated circuit fails to comply with the operating specification for the power supply. In response to the power supply failing to comply with the operating specification, the power failure detection circuit may generate a reset of the integrated circuit. The reset may cause the application to be restarted, such that the potentially corrupted memory cells are reinitialized, including reinitializing any mode registers. Alternatively, the reset may cause the operation of the integrated circuit to be temporarily suspended; however, continuous improper operation may be prevented.
Certain applications using an integrated circuit require very low power dissipation. For example, an application may be powered by a non-rechargeable battery that is required to last for several years. Continuous monitoring of the power supply by a power failure detection circuit may cause continuous power dissipation that exceeds the power that can be supplied by a battery over the required lifetime of the battery.
The present invention may address one or more of the above issues.